1Explosion proof mining dust samplerPreparation requirements before operation

1.1 Equipment Inspection

1. Explosion proof performance verification: Confirm that the explosion-proof label of the sampler (such as Ex d I Mb) matches the mine gas level, check that the explosion-proof shell has no cracks, the sealing rubber ring is intact, and the wiring port is tightly sealed. It is strictly prohibited to use it in non explosion proof state.

2. Core component inspection: Check if the sampling head, filter membrane clamp, and flow meter are intact. The filter membrane should be a glass fiber filter membrane that meets the standard. After weighing, record the initial mass and number it; Check the battery level or external power stability to ensure that the sampling duration requirements are met.

3. Functional testing: After turning on, test that the sampling pump starts and stops normally, the flow meter reading is stable, and the time setting function is accurate. If equipped with a sampling flow calibration device, it needs to be calibrated to the standard flow rate in advance (usually 10L/min or 15L/min, according to the testing standard).

1.2 On site preparation

1. Environmental assessment: Confirm that there is no gas accumulation (gas concentration ≤ 0.5%), no water spraying, no strong electromagnetic interference at the sampling point, and avoid dead corners of airflow generated by equipment operation. Determine the sampling location according to the "Coal Mine Dust Hazard Prevention and Control Specification" (such as 10-15m on the return air side of the mining face).

2. Safety protection: Operators should wear protective equipment such as dust masks, safety helmets, and mining lamps, check that the safety facilities around the sampling point are intact, and set up warning signs to prevent unrelated personnel from touching the equipment.

2、 On site operation steps

2.1 Equipment assembly

1. Installation of filter membrane: Use tweezers to pick up the pre weighed filter membrane and lay it flat inside the filter membrane clamp, ensuring that the filter membrane is wrinkle free and undamaged. After tightening the filter membrane clamp, install it onto the sampling head and tighten the sealing nut to prevent air leakage.

2. Connecting the pipeline: Connect the sampling head to the inlet of the sampling pump through a dedicated hose, check that the pipeline is not aging or blocked, ensure that the connection is tight and the direction is smooth, and avoid bending that affects the airflow.

2.2 Parameter Setting

1. Basic parameters: Set the sampling flow rate (such as 2L/min commonly used for respiratory dust sampling) and sampling duration (usually 15-60 minutes) according to the detection standards. Some equipment supports automatic timing, and the accuracy of the time needs to be confirmed in advance.

2. Auxiliary settings: If the sampler has data recording function, input information such as sampling point number, sampling date, operator, etc. to ensure data traceability.

2.3 Startup and Monitoring

1. Start the device: After confirming that the parameters are correct, press the start button and observe that the sampling pump is running normally and the flowmeter float is stable at the set value. If the flow fluctuation exceeds ± 5%, stop the machine to check the pipeline sealing or calibrate the flowmeter.

2. On site monitoring: During the sampling process, operators must not stay away from the equipment. Data such as flow rate, ambient temperature, and gas concentration should be recorded every 10 minutes. If there is any abnormal noise, sudden change in flow rate, or gas exceeding the limit, the equipment should be stopped immediately and evacuated to a safe area.

2.4 Shutdown and Sampling

1. Shutdown operation: After reaching the set duration, turn off the sampling pump first, and then cut off the power to avoid sudden shutdown causing membrane damage or data loss.

2. Filter membrane collection: Use tweezers to remove the filter membrane clamp, place the sampled filter membrane in a special sealed bag, label the sampling information to avoid contamination, and promptly send it to the laboratory for weighing and testing.

3、 Closing work after operation

3.1 Equipment Cleaning and Maintenance

1. Surface cleaning: Wipe the sampler housing and sampling head with a dry cloth to remove surface dust. It is strictly prohibited to rinse explosion-proof components directly with water.

2. Internal maintenance: Clean the residual dust in the filter membrane clamp, check the intake filter of the sampling pump, and replace it in a timely manner if there is any blockage; Place the equipment in a dry and ventilated explosion-proof warehouse to avoid mixing with corrosive substances.

3.2 Data organization and archiving

1. Data verification: Organize the records of flow rate, duration, environmental parameters, etc. during the sampling process, compare them with the automatically stored data of the equipment, and ensure data consistency.

2. Archiving and Preservation: Archive sampling records, filter membrane numbers, testing reports, and other materials in accordance with coal mine safety management requirements, with a retention period of no less than 2 years.

4Explosion proof mining dust samplerKey safety and operational taboos

It is strictly prohibited to operate equipment in areas where the gas concentration exceeds the standard (>0.5%), the roof is unstable, or there is water dripping, and it is not allowed to dismantle the explosion-proof casing without authorization.

If the filter membrane is found to be damaged or the pipeline leaks during the sampling process, the machine should be stopped immediately for replacement and resampling. Damaged filter membranes should not be used for testing.

Equipment charging must be carried out in an explosion-proof charging room on the ground. It is strictly prohibited to charge or replace batteries underground to avoid generating electrical sparks and causing safety accidents.

Regularly (at least once a month) conduct explosion-proof performance checks and flow calibration on the sampler, and the calibration records must be signed and confirmed by professionals.